UE::Mass::FEntityCollection Struct Reference

#include <MassEntityCollection.h>

Public Member Functions
	FEntityCollection ()=default
MASSENTITY_API	FEntityCollection (FMassArchetypeEntityCollection &&InEntityCollection)
MASSENTITY_API	FEntityCollection (const FMassArchetypeEntityCollection &InEntityCollection)
MASSENTITY_API	FEntityCollection (const TConstArrayView< FMassEntityHandle > InEntityHandles)
MASSENTITY_API	FEntityCollection (const TConstArrayView< FMassEntityHandle > InEntityHandles, FMassArchetypeEntityCollection &&InEntityCollection)
MASSENTITY_API void	AppendHandles (TConstArrayView< FMassEntityHandle > Handles)
MASSENTITY_API void	AppendHandles (TConstArrayView< FMassEntityHandle > Handles, FMassArchetypeEntityCollection &&InEntityCollection)
MASSENTITY_API void	AppendHandles (TArray< FMassEntityHandle > &&Handles)
MASSENTITY_API void	AddHandle (FMassEntityHandle Handle)
template<typename T > requires std::is_same_v<typename TDecay<T>::Type, FMassArchetypeEntityCollection>
void	AppendCollection (T &&InEntityCollection)
MASSENTITY_API bool	UpdateAndRemoveDuplicates (const FMassEntityManager &EntityManager, bool bForceOperation=false)
void	MarkDirty ()
bool	IsEmpty () const
MASSENTITY_API bool	IsUpToDate () const
TConstArrayView< FMassEntityHandle >	GetEntityHandlesView () const
TConstArrayView< FMassArchetypeEntityCollection >	GetCachedPerArchetypeCollections () const
TConstArrayView< FMassArchetypeEntityCollection >	GetUpToDatePerArchetypeCollections (const FMassEntityManager &EntityManager) const
TArray< FMassArchetypeEntityCollection >	ConsumeArchetypeCollections (const FMassEntityManager &EntityManager) &&

Detailed Description

Type represents a collection of arbitrary EntityHandles. Under the hood the type stores also an array of FMassArchetypeEntityCollection instances. These cached collections can be tested for being up to date, and re-created on demand, based on stored entity handles.

The type is intended to be used to collect entities available through different means: individual handles, handle arrays and or FMassArchetypeEntityCollection instances. Such accumulated handles can at any moment be turned into an array of up-to-date FMassArchetypeEntityCollection instance, which in turn is how entity sets are provided to MassEntityManager's batched API.

The biggest win while using this type is that the user doesn't have to worry about FMassArchetypeEntityCollection instances going out of date (which happens whenever the target archetype is touched in a way that changes internal entity indices). The type automatically updates the collections and caches the result.

Constructor & Destructor Documentation

FEntityCollection() [1/5]

UE::Mass::FEntityCollection::FEntityCollection ( )

default

FEntityCollection() [2/5]

UE::Mass::FEntityCollection::FEntityCollection ( FMassArchetypeEntityCollection &&  InEntityCollection )

explicit

The following constructor are equivalent to using the default constructor and subsequently calling AppendCollection or AppendHandles.

FEntityCollection() [3/5]

UE::Mass::FEntityCollection::FEntityCollection ( const FMassArchetypeEntityCollection &  InEntityCollection )

explicit

FEntityCollection() [4/5]

UE::Mass::FEntityCollection::FEntityCollection ( const TConstArrayView< FMassEntityHandle >  InEntityHandles )

explicit

FEntityCollection() [5/5]

UE::Mass::FEntityCollection::FEntityCollection	(	const TConstArrayView< FMassEntityHandle >	InEntityHandles,
		FMassArchetypeEntityCollection &&	InEntityCollection
	)

Member Function Documentation

AddHandle()

void UE::Mass::FEntityCollection::AddHandle

(

FMassEntityHandle

Handle

)

Appends the Handle to stored EntityHandles. Results in marking cached FMassArchetypeEntityCollection as dirty.

AppendCollection()

template<typename T >
requires std::is_same_v<typename TDecay<T>::Type, FMassArchetypeEntityCollection>

void UE::Mass::FEntityCollection::AppendCollection ( T &&  InEntityCollection )

inline

Based on the provided FMassArchetypeEntityCollection creates an array of entity handles and stores them. If up to this point the cached FMassArchetypeEntityCollection-s are consistent with stored EntityHandles then InEntityCollection gets stored as well, and stored collections are not marked as dirty.

AppendHandles() [1/3]

void UE::Mass::FEntityCollection::AppendHandles

(

TArray< FMassEntityHandle > &&

Handles

)

Appends Handles to stored EntityHandles. Results in marking cached FMassArchetypeEntityCollection as dirty.

AppendHandles() [2/3]

void UE::Mass::FEntityCollection::AppendHandles

(

TConstArrayView< FMassEntityHandle >

Handles

)

Appends Handles to stored EntityHandles. Results in marking cached FMassArchetypeEntityCollection as dirty.

AppendHandles() [3/3]

void UE::Mass::FEntityCollection::AppendHandles	(	TConstArrayView< FMassEntityHandle >	Handles,
		FMassArchetypeEntityCollection &&	InEntityCollection
	)

Appends Handles to stored EntityHandles. The second parameter is relevant if, at the moment of calling, the cached FMassArchetypeEntityCollection instances are in sync with stored entity handles (meaning all entities stored in EntityHandles are also captured by one of FMassArchetypeEntityCollection). If that's the case then the InEntityCollection gets stored along with existing collections. Otherwise, InEntityCollection will be ignored.

ConsumeArchetypeCollections()

TArray< FMassArchetypeEntityCollection > UE::Mass::FEntityCollection::ConsumeArchetypeCollections ( const FMassEntityManager &  EntityManager ) &&

inline

Updates cached archetype collections and returns the container with move semantics

GetCachedPerArchetypeCollections()

TConstArrayView< FMassArchetypeEntityCollection > UE::Mass::FEntityCollection::GetCachedPerArchetypeCollections ( ) const

inline

Retrieves the view to current contents of CachedCollections, which may be out of date. If you need valid, up-to-date collections call GetUpToDatePerArchetypeCollections instead.

GetEntityHandlesView()

TConstArrayView< FMassEntityHandle > UE::Mass::FEntityCollection::GetEntityHandlesView ( ) const

inline

GetUpToDatePerArchetypeCollections()

TConstArrayView< FMassArchetypeEntityCollection > UE::Mass::FEntityCollection::GetUpToDatePerArchetypeCollections ( const FMassEntityManager &  EntityManager ) const

inline

Fetches up-to-date FMassArchetypeEntityCollection instances matching stored entity handles.

IsEmpty()

bool UE::Mass::FEntityCollection::IsEmpty ( ) const

inline

IsUpToDate()

bool UE::Mass::FEntityCollection::IsUpToDate

(

)

const

Checks if cached collection data is up to date If CachedCollections are not up-to-date we reset them to cache the information (and make the subsequent tests cheaper) Note that, depending on the contents, the test might be non-trivial. Use responsibly.

MarkDirty()

void UE::Mass::FEntityCollection::MarkDirty ( )

inline

UpdateAndRemoveDuplicates()

bool UE::Mass::FEntityCollection::UpdateAndRemoveDuplicates	(	const FMassEntityManager &	EntityManager,
		bool	bForceOperation = false
	)

Results in duplicate handles being removed from EntityHandles, the cached collections being up-to-date and CollectionCreationDuplicatesHandling being set to FMassArchetypeEntityCollection::NoDuplicates

Parameters

bForceOperation

by default the entity handles will be re-exported only if CollectionCreationDuplicatesHandling == FMassArchetypeEntityCollection::FoldDuplicates (which means we cannot rule out that there are duplicates). Using bForceOperation = true will perform the operation regardless.

Returns

whether any duplicates were detected

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The documentation for this struct was generated from the following files:

• Engine/Source/Runtime/MassEntity/Public/MassEntityCollection.h
• Engine/Source/Runtime/MassEntity/Private/MassEntityCollection.cpp